Cita APA (7th ed.)

WILLIAMS, G. A., BOLEN, M. C., & DOERHOFF Ray B. (1973). Challenges to science physical science. Wbster Division, McGraw-Hill Book Company.

Cita Chicago (17th ed.)

WILLIAMS, George A., Max C. BOLEN, i DOERHOFF Ray B. Challenges to Science Physical Science. New York: Wbster Division, McGraw-Hill Book Company, 1973.

Cita MLA (9th ed.)

WILLIAMS, George A., et al. Challenges to Science Physical Science. Wbster Division, McGraw-Hill Book Company, 1973.

Atenció: Aquestes cites poden no estar 100% correctes.